/*       AAAA    CCCC   OOOO   TTTTTT   SSSSS  PPPPP      AA  AA  CC     OO  OO    TT    SS      PP  PP      AAAAAA  CC     OO  OO    TT     SSSS   PPPPP      AA  AA  CC     OO  OO    TT        SS  PP      AA  AA   CCCC   OOOO     TT    SSSSS   PP################################################################    ACO algorithms for the TSP    ################################################################      Version: 1.0      File:    ants.h      Author:  Thomas Stuetzle      Purpose: implementation of procedures for ants' behaviour      Check:   README and gpl.txt      Copyright (C) 2002  Thomas Stuetzle*//***************************************************************************    Program's name: acotsp    Ant Colony Optimization algorithms (AS, ACS, EAS, RAS, MMAS, BWAS) for the     symmetric TSP     Copyright (C) 2004  Thomas Stuetzle    This program is free software; you can redistribute it and/or modify    it under the terms of the GNU General Public License as published by    the Free Software Foundation; either version 2 of the License, or    (at your option) any later version.    This program is distributed in the hope that it will be useful,    but WITHOUT ANY WARRANTY; without even the implied warranty of    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    GNU General Public License for more details.    You should have received a copy of the GNU General Public License    along with this program; if not, write to the Free Software    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA    email: stuetzle no@spam informatik.tu-darmstadt.de    mail address: Universitaet Darmstadt                  Fachbereich Informatik                  Hochschulstr. 10                  D-64283 Darmstadt		  Germany***************************************************************************/#define HEURISTIC(m,n)     (1.0 / ((double) instance.distance[m][n] + 0.1))/* add a small constant to avoid division by zero if a distance is zero */#define EPSILON            0.00000000000000000000000000000001#define MAX_ANTS       1024    /* max no. of ants */#define MAX_NEIGHBOURS 512     /* max. no. of nearest neighbours in candidate set *//* Note that *tour needs to be allocated for length n+1 since the first city of a tour (at position 0) is repeated at position n. This is done to make the computation of the tour length easier */typedef struct {  long int  *tour;  char      *visited;  long int  tour_length;} ant_struct;extern ant_struct *ant;      /* this (array of) struct will hold the colony */extern ant_struct *best_so_far_ant;   /* struct that contains the best-so-far ant */extern ant_struct *restart_best_ant;  /* struct that contains the restart-best ant */extern double   **pheromone; /* pheromone matrix, one entry for each arc */extern double   **total;     /* combination of pheromone times heuristic information */extern double   *prob_of_selection;extern long int n_ants;      /* number of ants */extern long int nn_ants;     /* length of nearest neighbor lists for the ants'                                solution construction */extern double rho;           /* parameter for evaporation */extern double alpha;         /* importance of trail */extern double beta;          /* importance of heuristic evaluate */extern double q_0;           /* probability of best choice in tour construction */extern long int as_flag;     /* = 1, run ant system */extern long int eas_flag;    /* = 1, run elitist ant system */extern long int ras_flag;    /* = 1, run rank-based version of ant system */extern long int mmas_flag;   /* = 1, run MAX-MIN ant system */extern long int bwas_flag;   /* = 1, run best-worst ant system */extern long int acs_flag;    /* = 1, run ant colony system */extern long int elitist_ants;    /* additional parameter for elitist ant system, 				    it defines the number of elitist ants */extern long int ras_ranks;       /* additional parameter for rank-based version of ant				    system */extern double   trail_max;       /* maximum pheromone trail in MMAS */extern double   trail_min;       /* minimum pheromone trail in MMAS */extern long int u_gb;            /* every u_gb iterations update with best-so-far ant;				    parameter used by MMAS for scheduling best-so-far update				 */extern double   trail_0;         /* initial pheromone trail level in ACS  and BWAS *//* Pheromone manipulation etc. */void init_pheromone_trails ( double initial_trail );void evaporation ( void );void evaporation_nn_list ( void );void global_update_pheromone ( ant_struct *a );void global_update_pheromone_weighted ( ant_struct *a, long int weight );void compute_total_information( void );void compute_nn_list_total_information( void );/* Ants' solution construction */void ant_empty_memory( ant_struct *a );void place_ant( ant_struct *a , long int phase );void choose_best_next( ant_struct *a, long int phase );void neighbour_choose_best_next( ant_struct *a, long int phase );void choose_closest_next( ant_struct *a, long int phase );void neighbour_choose_and_move_to_next( ant_struct *a , long int phase );/* Auxiliary procedures related to ants */long int find_best ( void );long int find_worst( void );void copy_from_to(ant_struct *a1, ant_struct *a2);void allocate_ants ( void );long int nn_tour( void );long int distance_between_ants( ant_struct *a1, ant_struct *a2);/* Procedures specific to MAX-MIN Ant System */void mmas_evaporation_nn_list( void );void check_nn_list_pheromone_trail_limits( void );void check_pheromone_trail_limits( void );/* Procedures specific to Ant Colony System */void global_acs_pheromone_update( ant_struct *a );void local_acs_pheromone_update( ant_struct *a, long int phase );/* Procedures specific to Best Worst Ant System */void bwas_worst_ant_update( ant_struct *a1, ant_struct *a2);void bwas_pheromone_mutation( void );